Fig. 5

Effect of WSP-EA extracts on insulin-stimulated phosphorylation of the PI3K/Akt pathway. A–F Western blotting of insulin-stimulated phosphorylation of pIR, pIRS-1, pAkt and M-GLUT4 expression. TNF-α tumor necrosis factor alpha, ins insulin, WSP-EA white sweet potato ethyl-acetate fraction. TZD thiazolidinedione, pIR phosphorylation of insulin receptor, pIRS-1 phosphorylation of insulin receptor substrate 1, pAkt phosphorylation of protein kinase B, describe the scale of y-axis of each quantification: membrance glucose tranporter 4, T-GLUT4 total glucose transporter 4. Values were presented as mean ± SD as independent experiments performed in triplicate, and were analyzed using one-way ANOVA, followed by a post hoc Tukey’s test for multiple comparisons. The scale of y-axis of each quantification means ratio of candidate phosphorylated-protein expression to house keeping protein (B–D) or ratio of M-GLUT4 to total GLUT4. Different letters above the error bars indicate significant differences among treatments (P < 0.05)